Electron-discharge tube



May 8, 1928. 1,668,724

. s. LOEWE ELECTRON DISCHARGE TUBE Filed March 19. 1921 I Mae/#021 S/eymzma Zoewe.

2 -.that both cathode wires 3, which surround Fatented May 8, 1928.

UNITED STATES F Fl C E PATEN BIIGIUND L01, 0! BERLIN, GERMANY, ASSIGNOB 1'0 WESTERN EL ECTRIO 00!- rm, INOOBPORATED, 0! NEW YORK, N. Y., A CORPORATION 01' NEW YORK.

ELECTRON-DISCHARGE TUBE.

Application filed larch 18, 1821, Serial No. 468,845, and in Germany November 14, 1819.

This invention relates to electron discharge tubes having an anode, a cathode and a control electrode wherein either positive or negative impulses applied to said control electrode cause a reduction of current flow between said anode and cathode.

The invention has for an object to rovide various forms of such tubes, various methods of operation thereof and various systems in which they may be utilized, such as repeating, amplifying, detecting, oscillating or other systems.

ig. 1 illustrates'a form of tube embodying t e invention; Fig. 1 a modified form of cathode for the tube of Fig. 1; Fig. 2 a detectin and amplifying system; and Fig. 3 a mo ified form of amplifier.

Referring to the drawin in detail, 1 is an air-tight container insi e of which are the auxiliary electrode or grid 2, the cathode arrangement 3, and the anode 4;. The auxiliary electrode is inside the space surrounded by the cathode.

The cathode itself of Fig. 1 is so chosen the auxiliary electrode have their heating current flowing in parallel through them. The current is conveyed by the positive lead 5, and carried away in the ne ative leads 6 and 7. Slight ine ualities of lncandescence, may, if necessary, e-equalized by series re sistances. But as shown in Fig. 1' only one conductor need be used for the cathode at either end if care is taken to e ualize the separate parts of the cathode, tiat is the parallel wires, as to length and diameter. The cathode can consist of more than two parallel wires. The tube is most effective when the cathode surrounds the auxiliary electrode.

In Fig. 1 the anode 4 is shown as an elliptical sheet cylinder surrounding the cathode. The anode system can be arranged as desired, and can consist of wires arranged as is done in certain types of tubes, thereby forming a more complicated type of anode system.

The important features of the operation of the vacuum tubes according to the present invention are as follows: The current between the cathode system 3 and the anode system 4 will be weakened both with the positive and the negative charge of the auxlliary electrode 2, the, effect of a negative charge on the grid in reducing the space in drawing away from the cathode some of I the electrons or ions which normally would have reached the anode if the grid were not charged positively. The anode system, therefore, shows a maximum for a certain mean potential of the grid. The tubes are especially suitable as amplifiers and rectifiers for the purposes of wireless telegraphy and telep ony.

Fig. 2 shows an application of an amplifier circuit using the principle above outlined.

High frequency energy is received from antenna 8 by means of coil 9 and conducted to the electrode 2, which influences the flow of current between cathode 3 and anode 4 in such a way that the current produced by the auxiliary source 10 is weakened. This change in current will be conducted to the auxiliary electrode 2 of the next stage in the amplifying system through resistance 11 (choke coil, high resistance, transformer, or the like). Finally in the last sta e in the system the telephone 19 or a sim ar indicating instrument, relay or the like is connected.

It is evident that a special rectifying or detecting apparatus is not necessary since the high frequency oscillations immediately produce a unidirectional change in the current through the tubes. that is a weakening of the anode current for positive or negative charges of the auxiliary electrode. The

mean value of the anode current will conform to the envelope of the received high frequency waves.

In Fig. 2 a common heating battery 12 is provided for the cathode systems. The heating battery may be omitted if potassium cathodes, or the like, are employed. The important feature is that the arrangement of the system and the/method of operation of the tubes be such that the above mentioned unidirectional change shall occur. Instead of the separate batteries 10, a common anode battery can be used, making it possible to impress upon the systems following one another potentials of different value. There is a special advantage in that the potentials need amount to only a few volts so that the whole arrangement needs no very high value sources of electromotive force.

Other desired results, such as the generation of oscillations with the system according to Fig. 2 for the pur oses of heterodyne reception, are possible i a separate battery is connected in the circuit 9, 2 and 3, or if a separate anode 13 with battery 14 is used, which is coupled with the antenna 8 and coil 9. If the locally generated waves are high the action may be regarded as detection, while if it is comparatively low, it may be regarded" as a. modulating action.

In many cases it is desirable to obtain the unidirectional change, not as a weakening, but as an am lification of the current flow. This is possi le by using the arrangement shown in Fig. 3.

Resistance 15 is part of a circuit in which the unidirectional change appears as a cur rent weakening, as for instance in system 11 in the anode circuit of one of the tubes shown in Fig. 2. If we connect to this system in the usual manner a vacuum tube 16 with incandescent cathode, grid and anode, and allow a continuous current to flow thru the resistance 15 in such a way that the grid 17 is negatively charged, the current in the anode circuit of tube 16 can be decreased as desired. A decrease of the current in resistance 15, resulting from a signal wave impressed upon coil 9, will decrease the negative charge of grid 17 and therefore amplify the current flow in the anode circuit of tube 16 to actuate the signal receiving device 18. In this manner it is possible to reverse the efiect and hence, instead of a current weakening, to produce a corresponding current amplification. This is only one of the possible methods of obtaining the desired end.

The novel features believed to'be inherent in the invention are defined in the appended claims.

What is claimed is:

1. A detector, comprising a space current device. having a cathode. an anode. and a control electrode,- said cathode being arranged to substantially surround said control electrode, and means to apply to said electrodes, potentials so related that both postive and negative signal potentials impressed between said control electrode and cathode produce a unidirectional change in the space current between said anode and cathode.

produce a unidirectional change in the space current between said anode and cathode, said cathode surrounding said control electrode.

3. A detecting system, comprising a s ace current device having a cathode and tiree other electrodes, means including said cathode and two of said other electrodes to generate oscillations, and means including said cathode and a third of said other electrodes to detect the wave formed by combining said generated oscillations with an incoming signal oscillation.

4. In combination, a s ace current device having a cathode, an ano e and a control electrode, said anode comprising a cylinder surrounding said cathode and control electrode, and means for applying to said electrodes potentials so related that both positive and negative signal potentials impressed between said control electrode and said cathode produce a unidirectional change in the space current between said anode and said cathode, and means associated with said device responsive to said unidirectional change in space current to produce a component of amplified current of opposite sign from said first mentioned change in current.

5. In combination. a space current device having a cathode. a cylindrical anode and a control electrode, said cathode and control electrode being arranged within said anode so that both positive and negative signal potentials impressed between said control electrode and said cathode produce a unidirectional change in the space current between said anode and said cathode, and a repeater of the space current type coupled to said device responsive to said unidlrectional change in space current to produce a component of amplified current of opposite sign from said first mentioned change in current.

6. In combination, a space current device having a cathode, an anode and a plurality of other electrodes, means connected to said cathode and one ofsaid other electrodes for receiving wave energy, and means connectcd between said cathode and another of said other electrodes in energy transfer re lation to said first named means for producing rectified pulses in a circuit connected to said anode and cathode.

7. The combination in a signal receiving system of an electron discharge device having an electron emitting cathode, an anode, a third electrode and a discharge controlling member, circuit connections between said cathode and each of said other electrodes, means for impressing signaling potentials upon the circuit between cathode and third electrode, and means associated with the circuit between cathode and discharge controlling member for varying the resistance of thedcircuit between cathode and third electro e.

cuit. between cathode and dischar con- 10 trolling member for producing osc1 ations' therein and thereby var-yin the resistance of the circuit between cat ode and third electrode.

In witness whereof, I hereunto subscribe 16 my name this ninth day of February, A. D.

DR. SIEGMUND LOEWE. 

